Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
phong cong » phong chong, chong cong, phong dong
thong cong » trong cong, tong cong, thong thong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
tranh van » tran van, trinh van, thanh van
dan chan » dan gian, dan ca, van chat
chan ta » chan tha, nhan tai, nhan tao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thiet tach - canh tranh van ((phong cong) OR (thong cong)) dan chan ta~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - canh tranh van ((phong cong) OR (thong cong)) dan chan ta".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - canh tranh van ((phong cong) OR (thong cong)) dan chan ta*.